In related art, in a receiver or the like of a radio signal, an amplifier is used to amplify a faint signal. The amplifier is generally disposed on a first stage of a receiver, and a gain thereof and a noise figure thereof give a large influence on a reception sensitivity of a radio signal. Here, a noise figure is a ratio between an S/N (Signal to Noise) ratio of an input signal to an amplifier and an S/N ratio of an output signal to an amplifier. Normally, the larger a gain of an amplifier, the higher a reception sensitivity becomes. Further, the smaller a noise figure, the higher a reception sensitivity becomes. To improve characteristics of the gain and the like, for example, an amplifier has been proposed in which a P-type transistor and an N-type transistor for amplifying a signal are connected to a power supply in series (see, for example, Patent Literature 1).